The Secret Adversary by Agatha Christie is the first of five Tommy and Tuppence mystery adventures.

Quote:

Tommy and Tuppence, two young people short of money and restless for excitement, embark on a daring business scheme — Young Adventurers Ltd. Their advertisement says they are 'willing to do anything, go anywhere'. But their first assignment, for the sinister Mr Whittington, plunges them into more danger than they ever imagined!

This edition is more completely formatted then the edition on Project Gutenberg. This one has curly quotes/apostrophes, em dashes, and italics. The PG edition did not have italics.